Shipping containers are used to ship a wide variety of goods. One type of shipper forms a box that can be knocked down after use and then reused. This kind of container should be strong enough to carry its intended load safely and be as light as possible to reduce unnecessary shipping costs. It should also fold as compactly as possible to make return handling convenient.
One shipper of this kind is shown in U.S. Pat. No. 4,998,637. This patent shows a collapsible carton with a bottom and four sidewalls. The four sidewalls are hinged to the base and fold outwardly, forming a cross shape when knocked down. A separate top is used to position the walls when the carton is erect, and a disposable band holds the carton erect. This shipper is made of a single material.
Shipping crates have been made by, for example, using ribs to make the walls stiff, using thin cross sections elsewhere, and making openings through walls, all to make the resulting shipper lightweight. These techniques are illustrated in U.S. Pat. No. 5,076,457.
Other shipping containers have used fabric to close an open side. For example, the cargo container illustrated in U.S. Pat. No. 5,395,682 has a fabric wall that closes one side of the container. Containers that have fabric walls suspended from stiff frames, such as laundry hampers, are also well known, as shown, for example, in U.S. Pat. Nos. 3,233,644 and 3,358,725, or aircraft cargo containers as shown in U.S. Pat. No. 5,941,405.
Clearly, a shipping container's walls must not have any openings larger than the smallest item to be contained within. In addition there may be goods that require shipping in a closed container where air circulation is helpful. For example, baked goods, fruit, and fresh flowers may benefit from having air circulate, but insects and rodents should be excluded. Other goods have other ventilation requirements. Accordingly, there is a need for a lightweight shipping container that is collapsible, light weight, folds to a compact shape and yet also has sidewalls that keep small items in and allows control of air circulation through the container.